The use of additive manufacturing techniques is helping to increase efficiency in the aerospace industry. Parts manufactured by such techniques typically weigh less, reducing fuel consumption during operation. Moreover such techniques typically allow for the manufacture of complex geometries with shorter lead times. One such additive manufacturing technique is selective laser sintering (“LS”). LS is a layer-wise additive manufacturing technique in which electromagnetic radiation, for example from a CO2 laser, is used to bind a powder building material at select points to create a solid structure having a desired three-dimensional shape. It is known to use a polymer based building material powder in LS. For example, a building material that may be used with the present invention is a carbon filled PEKK compound with superior mechanical properties that is sold under the brand name OXPEKK®-ESD by Oxford Performance Materials, Inc.
A disadvantage of parts manufactured by the LS process, and particularly polymer parts, is that there is an upper limit on the temperature at which such parts can reliably operate and function. If the part is operated above this temperature, the polymer structure will degrade. Such high operating temperatures are routinely experienced in the flight structure of hypersonic vehicles wherein the structure inside the vehicle typically is subject to temperatures between 400 C and 600 C during operation of the flight. It is not possible to reliably use parts printed from polymers using the LS technique in this application because the polymer matrix will degrade. Instead, it is known to use high temperature alloys. These materials are notoriously difficult to work with and are expensive. A new approach to forming lightweight, temperature tolerant structures is required.
Aspects of the present invention are directed to these and other problems.